Muffler



Jan. 3, 1928. 1,655,230) w. A. KULL MUFFLER Original Filed Feb. 7. 1925 INVENTOR: F294, WALTEQ A. KULL,

BY I flzaamm dflmm HIS ATTORNEYS.

mama Jan. 3, 1928.

UNITED STATES PATENT OFFICE.

WALTER A. KULL, OI FLINT, MICHIGAN.

m Application filed February 7, 1925, Serial No. 7,552. Renewed Kay 18, 1928. I

This invention relates to mufllers and is herein shown as embodied in a muffler or silencer for reducing the noise of exhaust gases from an internal combustion engine,

An object of the invention is to provide a simple and eflicient muflier which can be inexpensively made from sheet metal. Another object is to rovide a'mufller which will'reduce the ve more effectively silence the exhaust.

To these ends and also to improve generally upon devices of the character indicated my invention consists in the various matters hereinafter described and claimed.

In the drawings, Figure 1 is a central longitudinal section, partly broken away.

Figure 2 is an end view.

Figure 3 is a section on line 33 of Figure 1.

Figure 4 is a section on line 4-4 of Figure 1;

The numerals 10 and 12 indicate circular b diaphragm members which are arranged in axial alignment and provided with concentric stepped portions 14, 16 and 18 projectinjg towards one another. The members are 0 be pressed out of sheet metal in the same dies. The member 10 is shown provided with a central opening 20 and the member 12 with a series of openings 22 near its periphery.- A tube 24, with perforations 26, has its ends sleeved over the steps 18 of smaller diameter outside of the central opening 20. The tube is preferably welded to one of said steps and left unsecured, as against longitudinal movement, with respect to the other.

A plate 28, having perforations 30, is wrapped. tightly around the intermediate steps 16 and provided with a longitudinal interlocking joint 32 which is foldeddown against the outer face at 34. This makes a cylinder which is preferably welded to the ,steps 16 and lies inside of the circle of openings 22 in the diaphragm member 12. An outer shell 36 is formed by bending a sheet longitudinal interlocking joint 38 folded against its outer face. The shell is preferably welded to the larger steps or flanges 14 of the diaphragms and extends axially beyond the diaphragms for a considerable dis; tance.

Fixed within one end of the outer shell or plate 36, as by welding, is a flanged head into an ocity of the gases andlike size and form so that they can 40 having an outlet opening communicating with a discharge pipe 42. A chamber 44 is thereby formed which receives the gases from the other end of the shell or plate 36 is a flanged head 46 having an inletopenin'g 48 which receives the burnt gases and delivers-them expansion or pressure reducing chamber 50. This ch cylindrical and, having only the thin outer shell 36 between it and the atmosphere, the

hot gases are initially cooled to a considerable extent and thus their velocity through the muflier is subsequently reduced. The ,70 I

gases pass rearwardly through the opening 20 into tube 24, thence'through perforations 26 and forwardly outside of tube 24 to the perforations 30 in after which they inside of the shell 36 to the openings 22.

Although the invention hasbeen described y reference to a specific construction, it should be understood that, in its broader aspects, form selected for mere illustrative purposes.

Iclaim:

1. In a muflier, a pair of flanged diaphragm members arranged in axial alinementand havin concentric stepped tions, one of said members being rovided with an opening at its center and t e other with openings near its periphery, a tube having its ends sleeved on the innermost stepped portions of the diaphragm, the in-, terior of the tube communicating with the first named opening, said tube being provided with openings at the end removed opening, a cylinder the cylindrical plate 28 forming with said cylinder a chamber communicating with the interior of the cylinder .at one end through the openings in said metal plate into cylindrical form with a cylinder, and at the other end in communication with the peripheral openings in one L of said diaphragms, said shell having its ends extended axially beyond the diaphragms, heads in the form of flanged discs secured in the ends of the shell and spaced a considerable. distance from said dial phragms to form expansion chambers, one of said expansion chambers being provided openings 22. Fixed within the amber is substantially again go rearwardly just it is'not necessarily limited to the on the next larger nesaaeo tures at alternate ends, one diaphragm having a central opening afi'ording communication between one expansion chamber and the innermost tube, the other diaphragm havin one or more peripheral apertures afiordmg communication between the external annular space within the outer wall and the second expansion chamber.

In testimony whereof I aflix my signature.

' WALTER A. KULL. 

